Antares rocket from Orbital Sciences could serve International Space Station.

For decades, the Space Shuttles were the primary way the United States transported cargo and people into low-Earth orbit. Upon retirement of the aging fleet of Shuttles, NASA has promoted a public-private partnership with companies that are developing new rockets for transport into low-Earth orbit. One of these companies, Orbital Sciences Corporation, is test-launching a new rocket design at NASA's Wallops Flight Facility in Virginia this week.

Orbital's design, known as Antares, is a multi-purpose middleweight rocket built to carry non-human payloads into space. A major part of its intended purview is robotic delivery to the International Space Station (ISS), an important task for supplying long-duration stays. This week's launch from Wallops is the first orbital test of Antares.

While NASA's Commercial Orbital Transportation Services (COTS) program for Station resupply only dates to 2006, Orbital has been developing rockets since 1990, beginning with the airplane-launched Pegasus. (For comparison, SpaceX was founded in 2002 and Virgin Galactic began operations in 2004.) Antares is based on Orbital's earlier designs, including the ground-launched Minotaur and Taurus rockets. However, the new design is much heftier, capable of carrying up to 6,120 kilograms (about 13,500 pounds), much higher than Minotaur's 1,730 kg maximum. According to the Orbital website, Antares is also capable of launching payloads on interplanetary trajectories.

For any rocket, the necessary fuel to achieve orbit is the heaviest component, outweighing the hardware and payload by a significant margin. Antares is a two-stage rocket, containing a liquid kerosene/oxygen primary booster and a solid-fuel secondary stage. The design emphasizes reliability (always a challenge for rockets) and low cost.

The Antares launch marks the first orbital flight from NASA Wallops, which historically has focused on balloon, sounding rocket, and other suborbital missions. However, the Lunar Atmosphere and Dust Environment Explorer (LADEE) probe will launch from Wallops later this year, the first Moon mission to begin from the Virginia facility.

This week's Antares test will not include Orbital's Cygnus payload craft, which (if successful) would be the module eventually supplying the ISS. Test launches involving Cygnus are scheduled for later this year.

We'll have someone on hand tomorrow to tour the facility and report on the launch, so check back then.

It seems like half the time a launch goes just a little wrong, the flexibility of a liquid-fueled, restartable second stage is critical in fixing the problem.

This is making me scratch my head too. You can't quite turn off a solid rocket and I'd be hard pressed to think the second and final stage was calibrated to the degree of accuracy needed to insert into a desired orbit.

Edit: According to wikipedia:

Quote:

The optional third stages planned, are the Bi-Propellant Third Stage (BTS) and an ATK Star 48-based third stage. BTS is derived from the Orbital Science's GEOStar spacecraft bus and uses nitrogen tetroxide and hydrazine for propellant; It is intended to precisely place payloads into their final orbits.[2] The Star 48-based stage uses a Star 48BV solid rocket motor and is planned to be used for higher energy orbits.[2]

It seems like half the time a launch goes just a little wrong, the flexibility of a liquid-fueled, restartable second stage is critical in fixing the problem.

I think this is an artifact of OSC's history. All their other rockets have been pure solid fuel designs. This appears to be a historical artifact due to their oldest designs being a derivative of the Minuteman ICBM. The Minuteman was an all solid fuel design because maintaining cryogenic fuel/oxidizers over multi-year periods would be difficult/expensive due to the extra infrastructure needed at the silos and because the third option, hypergolic fuels, was abandoned asap in favor of solid rockets for safety reasons: The chemicals used are highly toxic and any damage to the rocket is likely to result in an explosion.

The interesting question is their choice of a liquid fueled first stage for this one.

It's odd and less than optimal, but their previous rockets have been all-solid. They're basically replacing the first and largest 2 solid stages with one liquid stage. And the Cygnus spacecraft has some propulsion capabilities of its own with hydrazine thrusters for final orbit insertion and other maneuvers...they aren't going to do ISS rendezvous on solids. (wouldn't that be rather more exciting?)

The article doesn't mention one of the most interesting aspects of this launch. That is that the first stage of the Antares rocket is powered by two NK-33 engines originally built for the Soviet N1 moon rocket.

I've gotta get my butt over there for one of these launches. I've been jealous for a long time that I live 900+ miles from the Cape, but I only live 110 miles from Wallops...and my in-laws live only 20 miles from Wallops. Now I just need to find a time when there is a launch and a couple of days around it that I can take off to go view it. Oh and figure out a good viewing area.

I'd be interested to see a write-up comparing the various competitors for next-gen launch. Is anybody going to be remotely cost-competitive to SpaceX? Or did they really pull off a whole order of magnitude reduction in cost that no one else can match?

There's got to be a lot of aerospace company managers around the world scratching their heads wondering how SpaceX leapfrogged them so bad. If I were on the Boeing board, for example, I'd be furious. Of course, no heads will roll. "Accountability" really isn't in the modern corporate dictionary, unfortunately.

It seems like half the time a launch goes just a little wrong, the flexibility of a liquid-fueled, restartable second stage is critical in fixing the problem.

This is making me scratch my head too. You can't quite turn off a solid rocket and I'd be hard pressed to think the second and final stage was calibrated to the degree of accuracy needed to insert into a desired orbit.

Sometimes you go with the thing that works now, rather than the thing that might work better later.

I'm also confused by the second-stage solid-fuel rocket. Typically, solid-fuel rockets have immense thrust but shitty Isp - so they can be useful to punch a heavy payload through the densest part of the atmosphere, but they're exactly wrong for the long burn into orbit.

I'm wondering if there's some hidden efficiency I'm missing, or if it is just a case of "the devil you know." Or, of course, if I'm just totally wrong about how solid- and liquid-fuel rockets compare.*

* I am not a rocket scientist, but I did stay at a Holiday Inn last night do play a lot of Kerbal Space Program.

It seems like half the time a launch goes just a little wrong, the flexibility of a liquid-fueled, restartable second stage is critical in fixing the problem.

This is making me scratch my head too. You can't quite turn off a solid rocket and I'd be hard pressed to think the second and final stage was calibrated to the degree of accuracy needed to insert into a desired orbit.

Edit: According to wikipedia:

Quote:

The optional third stages planned, are the Bi-Propellant Third Stage (BTS) and an ATK Star 48-based third stage. BTS is derived from the Orbital Science's GEOStar spacecraft bus and uses nitrogen tetroxide and hydrazine for propellant; It is intended to precisely place payloads into their final orbits.[2] The Star 48-based stage uses a Star 48BV solid rocket motor and is planned to be used for higher energy orbits.[2]

I'm wondering if there's some hidden efficiency I'm missing, or if it is just a case of "the devil you know." Or, of course, if I'm just totally wrong about how solid- and liquid-fuel rockets compare.*

They're buying Aerojet AJ-26s (derived from the Russian NK-33), and that engine is meant to be started on the ground and isn't optimized for high altitudes. A liquid upper stage would require designing their own liquid engine, buying a different liquid engine from somewhere, or trying to heavily modify and rework the AJ-26s. Meanwhile, they're quite familiar with starting solid upper stages (their all-solid rockets need lots of stages because of the poor performance of solids).

So it's a liquid engine they can buy on the only stage it can go on, and an upper stage using an approach they're familiar with. Nowhere near an optimal combination, but one with low development risk. The smaller solid stage may be less troublesome to deal with as well.

It seems like half the time a launch goes just a little wrong, the flexibility of a liquid-fueled, restartable second stage is critical in fixing the problem.

I think this is an artifact of OSC's history. All their other rockets have been pure solid fuel designs. This appears to be a historical artifact due to their oldest designs being a derivative of the Minuteman ICBM. The Minuteman was an all solid fuel design because maintaining cryogenic fuel/oxidizers over multi-year periods would be difficult/expensive due to the extra infrastructure needed at the silos and because the third option, hypergolic fuels, was abandoned asap in favor of solid rockets for safety reasons: The chemicals used are highly toxic and any damage to the rocket is likely to result in an explosion.

The interesting question is their choice of a liquid fueled first stage for this one.

It actually makes sense. Although it seems like being able to turn the 2nd stage off is preferable, if something is going to go wrong, chances are the first stage is where it will be. The initial boost stage is always fraught with more dangers than the relatively easy going last push to orbit. Also, you should read Ars' recent article on the F-1, it explains the benefits of dense liquid fuels like kerosene quite well. Every (non military and non ATK affiliated) rocket guy I've ever spoken to has preferred liquid engines to solids for their versatility. (ATK loves solids for obvious reasons, and the military loves them because you can pack them in a warehouse for like 50 years and still light them up at a moment's notice.)Actually, I personally think NASA has gotten timid about solids (again, the non-ATK guys) because of things like Challenger and the lack of control. If you look at the competition for the SLS boosters, only one is solid fuel (again, thanks to ATK!).

I've gotta get my butt over there for one of these launches. I've been jealous for a long time that I live 900+ miles from the Cape, but I only live 110 miles from Wallops...and my in-laws live only 20 miles from Wallops. Now I just need to find a time when there is a launch and a couple of days around it that I can take off to go view it. Oh and figure out a good viewing area.

sounds like you just just go to the center (during business hours) - admission is free

"Rocket launches at WFF can be difficult to view due to the small size of some sounding rockets. Travel plans should not be based strictly on launch schedules. Times and dates can change due to weather and other factors. Rocket launches can be viewed from WFF Visitor Center grounds during operation hours or from south-facing areas on Chincoteague and Assateague islands in Virginia."

While NASA's Commercial Orbital Transportation Services (COTS) program for Station resupply only dates to 2006, Orbital has been developing rockets since 1990, beginning with the airplane-launched Pegasus.

Wrong. OSC was developing rockets since the mid 80s with the Transfer Orbit Stage (TOS). OSC and Martin Marietta shared design efforts, MM did 99% of the build and testing, and all funding flowed through OSC.

Now, if you meant to say "Orbital has been developing launch vehicles since 1990" then you'd be correct.

It seems like half the time a launch goes just a little wrong, the flexibility of a liquid-fueled, restartable second stage is critical in fixing the problem.

I think this is an artifact of OSC's history. All their other rockets have been pure solid fuel designs. This appears to be a historical artifact due to their oldest designs being a derivative of the Minuteman ICBM. The Minuteman was an all solid fuel design because maintaining cryogenic fuel/oxidizers over multi-year periods would be difficult/expensive due to the extra infrastructure needed at the silos and because the third option, hypergolic fuels, was abandoned asap in favor of solid rockets for safety reasons: The chemicals used are highly toxic and any damage to the rocket is likely to result in an explosion.

The interesting question is their choice of a liquid fueled first stage for this one.

The Titan ICBMs used nasty liquid fuels (e.g., N2O4), but they were in those silos for many years -- not really dropped ASAP.

The Minotaur first stage was based upon the Minuteman II ICBM. The Taurus first stage was a derivative from the Peacekeeper first stage (which Thiokol, now ATK, redesigned for OSC for a much softer ride -- IIRC the first few Taurus test launches used Peacekeeper first stages and dead weight on top of that first stage).

It's worth noting that the Cygnus sitting on top of the Antares uses the same hydrazine/nitrogen tetroxide hypergolics. The whole spacecraft only masses 1800 kg, though...a lot less of the nasty stuff to handle.

When I read articles like this, I begin to wonder how far off we really are from being able to develop a space elevator or star ram. While rockets are undeniably cool, I reckon they'll be looked back as being extremely inefficient once either of those launch systems is in place.

I also wonder which of those we're closer to being able to actually build. I'm guessing it'd be the star ram, as we don't have mass production of carbon nano-tubes sorted out yet. But the star ram will probably also still be levels of magnitude more expensive to run than a space elevator.

When I read articles like this, I begin to wonder how far off we really are from being able to develop a space elevator or star ram. While rockets are undeniably cool, I reckon they'll be looked back as being extremely inefficient once either of those launch systems is in place.

I also wonder which of those we're closer to being able to actually build. I'm guessing it'd be the star ram, as we don't have mass production of carbon nano-tubes sorted out yet. But the star ram will probably also still be levels of magnitude more expensive to run than a space elevator.

When I read articles like this, I begin to wonder how far off we really are from being able to develop a space elevator or star ram. While rockets are undeniably cool, I reckon they'll be looked back as being extremely inefficient once either of those launch systems is in place.

Both of those are very inflexible, and neither avoids the need for rockets. Getting to orbit with a space elevator requires climbing a large fraction of the way to geosynchronous orbit. The StarTram won't get you to any orbit without an apogee burn, and exposes the payload to extreme heating and deceleration once it leaves the launch tube. The space elevator is limited in throughput and takes a very long time to reach orbit. Both have to be built for a narrow range of payload sizes, both can only efficiently reach a small subset of orbits, and both can be shut down entirely by a minor problem with a single payload.

The bulk of the cost of space access is actually operations, and the large amounts of infrastructure and scheduling headaches will increase those costs. The next major cost is the vehicle, but the larger and more expensive part of a staged vehicle is far easier to recover and reuse than the upper stages, and companies are working on systems with varying degrees of reusability. The propellant costs for rockets are actually a very tiny fraction of the overall cost. With the range of capabilities and operational flexibility (and the lack of alternatives out of the atmosphere), rockets are here to stay.

And you may find it surprising, but rockets are the most efficient heat engines ever built...high combustion temperatures and rapid expansion with very little heat loss to the engine (as demonstrated by those walls not vaporizing when the engine's putting out multiple gigawatts of power...12 GW for each of the F-1 engines for the Saturn V). Almost all the chemical energy goes into accelerating the exhaust, efficiencies greater than 90% aren't unusual.

"A preliminary design for the explosives was produced. It used a shaped-charge fusion-boosted fission explosive. The explosive was wrapped in a beryllium oxide "channel filler", which was surrounded by a uranium radiation mirror. The mirror and channel filler were open ended, and in this open end a flat plate of tungsten propellant was placed. The whole thing was built into a can with a diameter no larger than 6 inches (15 cm) and weighed just over 300 pounds (140 kg) so it could be handled by machinery scaled-up from a soft-drink vending machine (indeed, Coca-Cola was consulted on the design)"

Bouncing sound from jaw. Not the least the nuclear explosive propellant vending machine. Wonder if it take dollars?

When I read articles like this, I begin to wonder how far off we really are from being able to develop a space elevator or star ram. While rockets are undeniably cool, I reckon they'll be looked back as being extremely inefficient once either of those launch systems is in place.

I also wonder which of those we're closer to being able to actually build. I'm guessing it'd be the star ram, as we don't have mass production of carbon nano-tubes sorted out yet. But the star ram will probably also still be levels of magnitude more expensive to run than a space elevator.

I've read about the Orion project before. Actually, I first heard about it when reading Footfall. Unfortunately, I don't expect NIMBYs will ever accept nuclear powered launches from anywhere near their vicinity. As a means of propulsion once in space, I think it'd definitely have more acceptance. But if we already have the mass in space, do we need something with that sort of horsepower?

When I read articles like this, I begin to wonder how far off we really are from being able to develop a space elevator or star ram. While rockets are undeniably cool, I reckon they'll be looked back as being extremely inefficient once either of those launch systems is in place.

Both of those are very inflexible, and neither avoids the need for rockets. Getting to orbit with a space elevator requires climbing a large fraction of the way to geosynchronous orbit. The StarTram won't get you to any orbit without an apogee burn, and exposes the payload to extreme heating and deceleration once it leaves the launch tube. The space elevator is limited in throughput and takes a very long time to reach orbit. Both have to be built for a narrow range of payload sizes, both can only efficiently reach a small subset of orbits, and both can be shut down entirely by a minor problem with a single payload.

The bulk of the cost of space access is actually operations, and the large amounts of infrastructure and scheduling headaches will increase those costs. The next major cost is the vehicle, but the larger and more expensive part of a staged vehicle is far easier to recover and reuse than the upper stages, and companies are working on systems with varying degrees of reusability. The propellant costs for rockets are actually a very tiny fraction of the overall cost. With the range of capabilities and operational flexibility (and the lack of alternatives out of the atmosphere), rockets are here to stay.

And you may find it surprising, but rockets are the most efficient heat engines ever built...high combustion temperatures and rapid expansion with very little heat loss to the engine (as demonstrated by those walls not vaporizing when the engine's putting out multiple gigawatts of power...12 GW for each of the F-1 engines for the Saturn V). Almost all the chemical energy goes into accelerating the exhaust, efficiencies greater than 90% aren't unusual.

One of the surprising things about a star ram was the amount of infrastructure required. I'd always imagined a launch vehicle taking off from almost ground level. Building a 6 mile high tower will probably be as much beyond our present capabilities as building a space elevator.

While the space elevator would be slow, I think it would turn out to be one of the more economical ways to get larger numbers of people into orbit quickly. Even if the trip took a week, once you're talking even tens of people, it'd probably be quicker than ferrying them up using every rocket we (as a planet) have.

You're right on the fragility though. An problem on a space elevator might not be as immediately catastrophic as a problem on a solid propellant rocket. But it's still a single point of failure and a bottleneck you can't get past until it's fixed. Same with the star ram. If a rocket blows up, you mourn the dead and then launch another one.

And yes, rockets are extremely efficient when it comes to fuel/power ratio. Unfortunately, they're also very complex, require a lot of planning and preparation before launching and a substantial amount of work before you can re-launch them. Both the star ram and the space elevator move that complexity to other areas that are easier to manage, and are almost immediately reusable. With either of them, we'd still need extra capability once in orbit though. But that's a lot less difficult than getting to orbit in the first place.

Unfortunately, I don't expect NIMBYs will ever accept nuclear powered launches from anywhere near their vicinity. As a means of propulsion once in space, I think it'd definitely have more acceptance. But if we already have the mass in space, do we need something with that sort of horsepower?

Orion has the capability to reach mission delta-v's of several percent of c, perhaps exceeding 5% c with modern materials. That's enough to allow us to actually launch probes to the nearby stars and see the results with a human lifetime. Fusion versions would do 2-3 times better, bringing time to the nearest stars down to a few decades.

Closer to home, they would give us the capability to move large asteroids around in a reasonable amount of time and make manned missions to the outer system...Saturn in months rather than years. They wouldn't have hours of lightspeed lag to deal with and could carry additional craft and propellant for landings and sample return from the various moons.

While the space elevator would be slow, I think it would turn out to be one of the more economical ways to get larger numbers of people into orbit quickly. Even if the trip took a week, once you're talking even tens of people, it'd probably be quicker than ferrying them up using every rocket we (as a planet) have.

Dragon is already to have the capability to carry 7 people each flight, and only needs to support them for hours. An elevator requires many times more supplies, life support, waste handling equipment, room to move around in, etc.

Launching people is one of the things a space elevator is definitely not suited for. Apart from the need for extended duration living arrangements, it necessarily requires crawling through the densest part of the radiation belts for several days. They're only good for bulk radiation-tolerant cargo.

I'm also confused by the second-stage solid-fuel rocket. Typically, solid-fuel rockets have immense thrust but shitty Isp - so they can be useful to punch a heavy payload through the densest part of the atmosphere, but they're exactly wrong for the long burn into orbit.

I'm wondering if there's some hidden efficiency I'm missing, or if it is just a case of "the devil you know." Or, of course, if I'm just totally wrong about how solid- and liquid-fuel rockets compare.*

* I am not a rocket scientist, but I did stay at a Holiday Inn last night do play a lot of Kerbal Space Program.

Heh - I was thinking the same thing - and with the same caveat Thanks to the good folks on this thread for answering the question.

And you may find it surprising, but rockets are the most efficient heat engines ever built...high combustion temperatures and rapid expansion with very little heat loss to the engine (as demonstrated by those walls not vaporizing when the engine's putting out multiple gigawatts of power...12 GW for each of the F-1 engines for the Saturn V). Almost all the chemical energy goes into accelerating the exhaust, efficiencies greater than 90% aren't unusual.

There's a lot more to efficiency in getting something to orbit than just a single thermodynamic number for how much of the energy in the fuel is turned into thrust. The overwhelming majority of the energy expended by a rocket is used in transporting fuel to where it's consumed. In practical real world terms energy/cost per kg put into orbit is the relevant number and rockets use enormously more energy than a car ascending a space elevator would; and the size of a rocket needed to convert a highly eliptical orbit resulting from something dropped off the side of an elevator below geo into a roughly circular leo orbit is much smaller that what would be needed to boost it directly; even using conventional high thrust engines instead of a high Isp system like an ion drive (or hall effect thrusters, vasimir, etc) or even 'free' propulsion via a solar sail or electrodynamic tether.

There's a lot more to efficiency in getting something to orbit than just a single thermodynamic number for how much of the energy in the fuel is turned into thrust. The overwhelming majority of the energy expended by a rocket is used in transporting fuel to where it's consumed.

That energy isn't just lost, it's there as propellant which is now moving with the rocket, ready to be accelerated backwards for producing thrust. Efficiency of applying propellant energy to the payload does go down as overall delta-v goes above the exhaust velocity, as even the exhaust ends up moving in the same direction as the payload toward the end of the burn, but it's not as terrible as it's made out to be. The propellant costs for a launch from Earth are a tiny fraction of the launch costs...a Falcon 9 launch costs something like $15/kg in propellant.

A space elevator reduces energy costs by taking much of the energy from the rotation of the Earth. However, energy costs are still going to be substantial, and system efficiency is likely to be very low...a typical proposal is to have the climber powered by laser from the ground, something that will involve a lot of losses. Total energy costs may not be any lower.

When I read articles like this, I begin to wonder how far off we really are from being able to develop a space elevator or star ram. While rockets are undeniably cool, I reckon they'll be looked back as being extremely inefficient once either of those launch systems is in place.

I also wonder which of those we're closer to being able to actually build. I'm guessing it'd be the star ram, as we don't have mass production of carbon nano-tubes sorted out yet. But the star ram will probably also still be levels of magnitude more expensive to run than a space elevator.

I'm not familiar with the star ram, but the space elevator is a lot farther off than the futurists want you to believe, and isn't nearly as attractive as you'd think. There are a lot of subtle problems. For example, by necessity, a space elevator passes directly from the ground through the ionosphere, meaning that the entirety of the Earth's ionosphere will try to discharge through any space elevator cable to the ground, and no one knows how to prevent that from happening. Just because the gravitational and material mechanics can be made to work out assuming perfect carbon nanotube manufacture doesn't mean it works in practice once you're no longer in a vacuum.

I personally suspect that the only real improvements we can expect are denser fuel sources and lighter construction.

but the space elevator is a lot farther off than the futurists want you to believe, and isn't nearly as attractive as you'd think. There are a lot of subtle problems. For example, by necessity, a space elevator passes directly from the ground through the ionosphere, meaning that the entirety of the Earth's ionosphere will try to discharge through any space elevator cable to the ground, and no one knows how to prevent that from happening.

This "problem" just doesn't exist...for starters, 100 km of elevator tether isn't likely to be particularly conductive if not carefully designed to be. It wouldn't discharge the entire ionosphere even if it were...the sparse plasma of the ionosphere just doesn't behave that way. The main technical problem apart from materials is atomic oxygen, which is constantly produced by solar radiation and will attack virtually anything remotely oxidizable, including molecular oxygen. (this being what forms the ozone layer in the upper stratosphere)

But what really poses a problem are the operational complexities and limitations. The tether can only lift or lower a few payloads at a time, and can only operate in one direction at a time. Transporting a single payload takes weeks (longer if weather interferes with the ground-based power beams) and requires spending an extended amount of time in the Van Allen belts. And the space elevator will require careful shepherding of satellites and miscellaneous junk into orbits that don't intersect it. There are strict limits on payload mass, launching a larger payload would require extensive upgrades that would take the elevator out of commission until they are completed. And not only does it require cooperation from everyone else in orbit to not be subject to debris hazards from satellites, it itself poses a major debris hazard to those satellites if there's a break.

A Mars elevator makes more sense. Usage rate will be low and demand predictable, material requirements are far lower and orbital space is far less crowded. They make even more sense for asteroids, easily providing a couple km/s starting delta-v. But for Earth? They're far than ideal.

When I read articles like this, I begin to wonder how far off we really are from being able to develop a space elevator or star ram. While rockets are undeniably cool, I reckon they'll be looked back as being extremely inefficient once either of those launch systems is in place.

I also wonder which of those we're closer to being able to actually build. I'm guessing it'd be the star ram, as we don't have mass production of carbon nano-tubes sorted out yet. But the star ram will probably also still be levels of magnitude more expensive to run than a space elevator.

I've read about the Orion project before. Actually, I first heard about it when reading Footfall. Unfortunately, I don't expect NIMBYs will ever accept nuclear powered launches from anywhere near their vicinity. As a means of propulsion once in space, I think it'd definitely have more acceptance. But if we already have the mass in space, do we need something with that sort of horsepower?

Loved that book too! Well, the bomblets would be clean, the EMP confined to a limited area, and as a method of lofting large (I mean, they can be REALLY large) spacecraft out of our gravity well, Orion would be very cost effective -even in today's dollars. Especially when one considers that even the smaller interplanetary version configuration could loft a mass to LEO that is four times the size of the ISS in ONE launch. (Now THAT'S one roomy ship!) Hell, they were seriously talking about launching an entire moon base with one ship:"...They talked of sending men to Mars by 1965 and Saturn by 1970. Apollo engineers struggled with weightsaving technologies such as five stage rockets for a moon shot carrying three astronauts.

Then there's the speed angle: 8 - 10% of the speed of light was considered doable. And this was with 1958 technology. An antimatter drive could theoretically go much faster -but antimatter production is horrifically expensive -and containment is rather, ah, ticklish.